Using capacitance arrays in integrated circuits is already known and has been implemented in a number of different circuits. Examples of such integrated circuits with capacitance arrays are digital/analogue converters or tuneable crystal oscillators.
Previously, the capacitance arrays contained in the integrated circuits have been tested mainly by analogue means, e.g. in such a manner that a voltage or current measurement is used for checking whether there is a short circuit between the capacitor plates of the individual capacitances in the capacitance array. As a rule, these tests provide information only on whether the capacitance tested is defective or operable. This method does not provide accurate quantitative information about the value of the capacitance tested. This is a disadvantage particularly when testing weighted capacitance arrays since the usefulness of the circuit utilizing the capacitance array, e.g. digital/analogue converter or crystal oscillator circuit, depends substantially on the required capacitance values in the capacitance array being maintained.